Field of the Invention
The present invention relates to a novel process for preparing halogenated di-substituted benzylamines, particularly halogenated dialkylbenzylamines.
Description of Related Art
The preparation of halogenated dialkylbenzylamines is known from the prior art. For example, WO 2012/139561 A1 describes a process for preparing aromatic or heteroaromatic amines from the corresponding aryl and heteroaryl halides or sulphonates in the presence of a catalyst and a base.
US 2007/0073086 A1 describes a process for preparing diphenylamines wherein aryl halides are reacted with aromatic amines in the presence of an organic solvent, alkali metal hydroxide and a phase-transfer catalyst.
Similarly U.S. Pat. No. 3,646,147 P describes a process for preparing tertiary amines wherein alkyl chlorides are reacted with primary amines in the presence of alkali metal iodides as catalysts.
WO 2008/125592 A1 likewise discloses a process for preparing o-chloromethylphenylglyoxylic esters. This document describes the synthesis of 2-chlorobenzylmorpholine wherein morpholine is added to a solution of 2-chlorobenzyl chloride in toluene and 15% strength aqueous sodium hydroxide solution.
EP 0 034 425 A1 describes a process for preparing tertiary amines wherein starting from a mono- or di-secondary amine said amine is arylated via an Ullmann condensation with a di-iodoaryl compound in the presence of a copper catalyst.
WO 2013/017611 A1 likewise discloses a process for preparing N,N-dialkylbenzylamines. This process comprises reacting dimethylamine and 2-chlorobenzyl chloride in a molar ratio of 3:1 or greater.
Disadvantages of the processes described in the prior art include the use of costly catalysts or the use of a large excess of secondary amines which entails costly and inconvenient removal of the amine.
The problem addressed by the present invention was therefore that of providing a novel process for preparing halogenated di-substituted benzylamines, particularly halogenated dialkylbenzylamines, wherein the use of catalysts is not necessary, the reaction mixture does not comprise an excess of the secondary amine and yet the end product is obtainable in high purity and yield.